Semiconductor Nanostructures “Lendület” Research Group

Introduction

Welcome to the Adam Gali group at Wigner Research Centre for Physics Our group’s research focuses on theoretical and experimental characterization of point defects in semiconductors and semiconductor nanostructures. We are developing and implementing new techniques for introducing dopants and defects in semiconductor (nano)structures, and studying their properties by experimental and theoretical spectroscopy tools.

We are looking for an experienced and ambitious researcher with a background in optically detected magnetic resonance (ODMR) techniques to study solid state qubits. This is a Postdoc job that can be turned to tenure track position for qualified researchers. Email your CV to Adam Gali!

Highlights

Our group member, Viktor Ivády, has been honored by receiving the Premium Postdoctoral Fellowship from the Hungarian Academy of Sciences. Congratulations!

We use density-functional theory calculations to see if other group-IV elements—namely, germanium, tin, and lead—in a vacancy center exhibit similar optical properties to silicon but with improved spin properties that permit an economical cooling system. We develop a new theory for understanding the interaction of light and magnetic fields with these color centers, and we explore how the dynamical motion of the atoms strongly affects the magneto-optical properties of the color center. By combining our theory with density-functional theory calculations, we find that lead-vacancy color centers should have favorable optical and spin properties for operating at room temperature.

Our ab initio simulations determined the magneto-optical properties of the neutral divacancy in silicon carbide that contributed to understanding its qubit operation carried out by Prof. David D. Awschalom group.

Our ab initio study identified the nitrogen terminated (111) diamond surface to host shallow nitrogen-vacancy centers for quantum sensing. In cooperation with Alex Retzker we showed, that special quantum simulations can be carried out with the nitrogen nuclear spins in this system

We investigated the electron-phonon coupling in small diamond cages called diamondoids. These quantum systems are mostly modelled within the Born-Oppenheimer approximations, where the coupling between the electrons and vibration modes is not fully taken into account. In our study we shown that the severe electron-phonon coupling is a key point to properly describe the overall lineshape of the experimental photoemission spectrum. Our method goes beyond the typical Born-Oppenheimer approximation, where the electrons are pure electron-like quasi-particles. In our model, we deduced a link between the many-body perturbation approach of the electron-phonon coupling and the well-known Jahn-Teller effect.